Technical Field
This disclosure relates generally to storing data on a physical recording medium, and more specifically, to reclaiming storage blocks of the physical recording medium.
Description of the Related Art
Modern storage systems may arrange data on a recording medium using a log-structure in which data may be written at an append point that starts at an initial portion in the medium and advances forward as writes are performed. When a piece of data is initially stored and then modified, rather than replacing the original instance on the medium at its current location, the modified data is written to the append point. The original instance is then marked as invalid since storage is no longer warranted. In the interim, the original instance may remain on the medium occupying space. To prevent a storage system from eventually becoming full, storage blocks may be reclaimed so that they can be used again for storage. In some instances, reclaiming storage blocks may include relocating and/or consolidating data elsewhere if is still warrants being stored.
Storing data using a log structure can be advantageous in many circumstances. For example, if data becomes corrupted as it is being stored, the log structure can be replayed in order to potentially recover previous instances of the data. Solid-state devices can also benefit from using a log structure since it can produce a more even distribution of writes across a medium, resulting in less wear leveling. In some instances, however, implementing a log structure may be more difficult than other storage schemes because it typically results in the generation of additional metadata.